Lower alkylene and lower alkylenephenylene-lower alkylene polyamine bis n, n&#39;-lower alkylene di and tri carboxylic acids, esters, salts, and chelates



United States Patent LOWER ALKYLENE AND LOWER ALKYLENE- PHENYLENE-LOWER ALKYLENE POLYAMINE BIS N,N' LOWER ALKYLENE DI AND TRI CAR- BOXYLIC ACIDS, ESTERS, SALTS, AND CHE- LATES William M. Ramsey, Downey, and Charles Kerzerian, Los Angeles, Caiit'y, assignors to Victor Chemical Works, Chicago, Ill., a corporation of Illinois No Drawing. Filed June 17, 1959, Ser. No. 820,872

25 Claims. (Cl. 260-429) This invention relates to products, and methods of producing same, from the group consisting of:

(a) A compound essentially of the formula:

wherein A, and A are the same or different members of the group consisting of alkylene and alltylene-phenylenealkylene groups; Y Y and Y are members of the same or different alkyl group or hydrogen, and at least one of Y and Y is an alkyl group; k is a positive integer of not less than 1 and not more than 7; Z and Z are the same or different bis-adduction reaction residues of a member of the class consisting of unsaturated polycarboxylic acids, lactones, and salts (includes acid addition salts and salts having a cation bonded to a carboxyl group) thereof;

(b) Chelates comprising polyvalent metal ion; and

(c) esters comprising the product of (a) and a lower alkyl substituent bonded to at least one carboxyl group.

Stated in a different manner, this invention relates to bis-adductlon products, and methods of producing same, from the group consisting of:

(a) A compound essentially of the formula:

the product of (a) and a wherein A, and A are the same or dilferent members of the group consisting of alkylene and alkylene-phenylene alkylene groups; Y Y and Y, are members of the same or ditlerent alkyl group and hydrogen, and at least one of Y and Y is an alkyl group; k is a positive integer of not less than 1 and not more than 7; R and R are members of the class consisting of hydrogen, lower alkyl groups, COOM groups, and lower alkylene-COOM groups; R, and R are members of the class consisting ot lower alkylene groups and lower alkylene groups having an additional free bond; n is a positive integer of not less than 1 and not more than 2; R and R are lower alkylene groups when n is 1; R and R are members of the class consisting of hydrogen, lower alkyl radicals, and lower alkylene-COOM groups; and M in the above formula is the same or different radical from the class consisting of hydrogen, organic base radicals, inorganic base radicals, and lower alkyl radicals;

(b) Chelates comprising the compound of (a) and a polyvalent metal ion;

(c) Salts (i.e., includes acid addition salts) of the compound of (a); and

(d) Lactones of (a).

The term alkylene" is herein (includes claims) intended to include alkyl and substituted alkyl radicals having an additional free bond. The terms alkenyl, alkyl" and phenylene" are herein (includes claims) intended to 3,077,487 Patented Feb. 12, 1963 'ice include substituted alkenyl, alkyl and phenylene groups, respectively. The term carboxyl is herein intended to include the group. The phrase unsaturated polycarboxylic acids" is sometimes herein intended to include acyclic ethylenically unsaturated polycarboxylic acids, lower alkenyl polycarboxylic acids, salts thereof, and their anhydrides.

Y Y and Y;, in the above formulae may be hydrogen or an alkyl group such as unsubstituted alkyl, alkylaryl, hydroxyalkyl, hydroxyalkylaryl, hydroxyalkyloxyaryl, carboxyalkyl and alkylcarboxylates, hydroxyalkylpolyoxyalkyl (e.g., -(CH CH O) H), and alkylphosphonic acid alkylphosphonate, alkylsulionic acid, and alkylsulfonate radicals. In the formulae, A, and A are the same or difierent members of the group consisting of lower alkylene and lower alkylene-phenylene-lower alkylene radicals.

R and R in the above formula may be hydrogen, a lower alkyl group, a lower alkylene-COOM group, or a COOM group. R and R are lower alkylene groups such as methylene or a lower alkylene group having an additional free bond; R and R are lower alkylene groups such as methylene. R and R may be hydrogen, a lower alkyl radical, or a lower alkylene-COOM radical. M may be the same or different radical from the group consisting of hydrogen, an organic base radical such as triethanolamine, an inorganic base radical such as sodium and NH or a lower alkyl ester radical such as -CH CI-I FIRST STEP IN PREPARATION OF OUR PRODUCTS Products of the above formulae may be produced by first reacting an organic poly primary amine with one mole of a member from the group consisting of unsaturated polyearboxylic acids, salts thereof (e.g., alkali metal and tertiary amine salts) and esters thereof, for each primary amine group present in the organic poly primary amine, as shown in copending Kezerian and Ramsey application entitled Bis-Adduction Products and Methods of Preparing Same," Ser. No. 800,116, filed March 18, 1959. The adduction reaction involves a reaction between the nitrogen atoms of the amine and the double bond of the acid, ester or salt thereof. This reaction may be illustrated by the following equation:

lower alkylene-N-lower alkylene radical (a) that is repeated as desired (the term desired" may be zero) number of times, (b) wherein each lower alkylene radical may be the same or different, and (0) wherein each repeating radical need not be the same as the preceding one. The

0 lower alkylcne-N-lower alkylene radical 1 The salts formed in accordance with the above reaction may be converted to the free amino acids by treatment with stronger acids. In most cases the free amino acid is precipitated and may be separated by filtration. In some instances where the free amino acid is soluble it may be separated by ion exchange methods.

As another illustration of the above adduction reaction, itaconic acid may be reacted with triethanolamine to form a salt and the salt may be then reacted with p,p'-methylene-dianiline to form p,p'-di-N-pyrrolidone-2,4-carboxylic acid. This reaction is shown below:

CHiCOOTea Hz-CO Te lrn CH2CHOO OH] 2 Suitable organic poly primary amines for use in the above reaction inclwde ethylenediamine, diethylenetriamine, tetraethylenepentamine, propylenediamine, hexamethylenediamine, beta hydroxypropylene-diamine, 2,2- diaminodiethyl ether, 2,2'-diaminodiethyl sulfide, phenylenediamines, 2,2, 2"-triaminotriethylamine, benzidine, diaminocyclohexane, diaminophenol, polyglycoldiamine, lysine, ornithin, methylenedianiline, o-aminoethyl aniline, ammelene, melamine, tris-3-aminopropylamine, tris-2- aminoethylamine, etc.

The process for the preparation of the adduction products of the above. reaction is accomplished by heating a basic aqueous solution or melt of the poly primary amine with the unsaturated polycarboxyiic acid for a period of time suflicient to complete the reaction (from a few hours to a few days). The molecular proportions of the reactants are approximately one mole of the unsaturated polycarboxylic acid per primary amine group present in the poly primary amine. The alkalinity of the reaction mixture is established and maintained by means of a strong inorganic base or nonreactive strong organic base. Suitable bases include NaOl-I, KOH, triethylamine, triethanolamine, and the like. The basicity of the reaction mixture is preferabl9licid ata pHabove 95. The speed of the reaction may be varied to some extent by varying the temperature and pressure conditions under which the reaction is carried out. In general, the most satisfactory procedure is to heat the mixture to a refluxing temperature at atmospheric pressure for a period of at least several hours. It is essential to maintain alkaline reaction conditions during such polyadduction reactions in order to prevent unnecessary complex side reactions involving carboxylic hydrogen with excess amine groups.

SECOND STEP IN PREPARATION OF OUR PRODUCTS The products of this invention are prepared from the products of the reaction referred to above as the first step, by reacting the hydrogen atom of one or more of the secondary amino groups of the product of the first step with products that replace the hydrogen with alkyl groups such as hydroxyalkyl, hydroxyalkylaryl, carboxyalkyl, hydroxyalkylpolyoxyalkyl, and alkylphosphonic groups. The product of the first step may be reacted with products such as chloropropanol, ethylene chlorohydrin, chloropropanediols, benzyl chloride, dodecyl chloride, stearoyl chloride, ethylene dibromide, tetraglycol chloride, iodobenzene, chloronaphthalene, chlorophenol, cyclohexyl bromide, chlorosuccinic acid, chloroacetic acid, chlorohutyric acids, pheuylchloroacetic acid, chloromethylphosphonic acid, diphenylphosphorus oxychloride, ethylene oxide, styrene monoxide, epichlorohydrin, glycidol, phenyl glycidol, allyl alcohol, crotonic acid, ethylene cyanohydrin, acetone cyanohydrin, hydroxypropionitrile, acrylonitrile, hydroxymethane sulfonic acid (formalin plus sodium bisulfite) and glycidol phenyl ether.

Examples I-VIII, infra, illustrate the first step in our method wherein an organopolyprirnary amine is reacted with one mole of a member from the group consisting of unsaturated polycarboxylic acids or lactones, salts thereof, and esters thereof, for each primary amine group present in the organo-polyprimary amine.

Examples lX-XXXiV, infra, illustrate either (a) the second step of our method wherein the hydrogen atom of at least one of the secondary amino groups of the product of step one is replaced with various alkyl groups (includes substituted alkyl groups), or (b) the preparation of derivatives of (a).

Examples XXXVXXXX, infra, show some of the outstanding properties of our products and the uses to which they may be applied. Example XXXV shows that these products are outstanding chelants or chelating agents. Example XXXVI shows that they are elfective in removiug rust and oxide coatings from metal surfaces. Example XXXVI I shows that these products inhibit the destructive effects of mineral acid on iron. Example XXXVIII illustrates their use in resin formulations. Example XXXIX discloses the use of our products in metal coating baths. Example XXXX illustrates their use in treating plant chlorosis.

EXAMPLE I Ethylenediamine Bis-N,N'-Succinic Acid the dropwise addition of 700 g. of 50% by weight NaOH (8.75 moles). Extreme caution should be exercised at this stage, since if NaOH accumulates in quantity unreacted in the reaction media, it may suddenly react with near-explosive violence. However, during this neutralization-hydrolysis, the temperature should not be allowed to drop below 70 C. in order to prevent the separation of sodium maleate.

The hot reaction solution of disodium maleate was treated with 170 g. of 70% by weight ethylenediamine (2.0 moles). The solution was then digested above 95 C., and finally treated under reflux for 48 hours in a stainless steel reactor. The final reaction solution (36 B6.) was cooled to room temperature, then acidified to a pH of 2.0 with 680 ml. of concentrated HCl (8.2 moles). When no further product separates (6-16 hours), the White slurry of micro-crystals was filtered, washed with three, 250 ml. portions of water, and then dried to a constant weight at 90-l00 C. The products melted at 220-222 C. and constituted 540 g. yield (92.2% of the theoretical 548 g. yield).

The product, ethylenediamine bis-N,N'-succinic acid (EDDS-4H), was found to be only slightly soluble in water and insoluble in ethanol, acetone, benzene, and most organic solvents. 0.77 gram of the product dissolved in 100 ml. of H at 28 C.

A 292 g. (1.0 mole) portion of EDDS-4H was dissolved in 400 ml. of water containing 160 g. (4.0 moles) of NaOH. The solution was cooled, and acidified to a pH of 2.0 with 330 ml. of concentrated HCl (4.0 moles). The solution was seeded, and was set aside (undisturbed) for 24 hours, filtered, and then washed with 500 ml. of water. The product was air dried to the dihydrate. Recrystallization yielded 280 g., that is, 85.4% of the theoretical yield of 328 g. The product was divided into two portions: (A), which was analyzed as such, and (B), which was dried to a constant weight at 90 C. A pentahydrate of EDDS4H was prepared by passing boiling water through a pad of EDDS-4H; rapid cooling of the clear filtrate yielded long, transparent needles (C). Analytical data have confirmed the samples as:

(A) EDDS-41-I-2H O (B) EDDS-4H, anhydrous (C) EDDS-4H-5I-I O Molecular weight determined by pH titration:

(B) C li N O Found 290, theory 292; inflections at pH of 5.5, 8.7 and 11.25.

(C) C H N O '5H O: Found 383, theory 382; inflections at pH of 5.5, 8.7 and 11.25.

Total N values determined by Kjeldahl:

(i3) C H N o -Percent N: Found was 9.51; theory (C) C H N O '5H OPercent N: Found was 7.34;

theory 7.33.

A 269.5 g. sample of EDDS4H-2H O (0.8216 mole) was dried at 95 C. to a constant weight. The 28.5 g. (1.583 moles) loss of water corresponds to the theoretical loss from the dihydrate.

The reactions were usually carried out in metal reactors, preferably stainless steel, in order to avoid contamination by glassware. The conditions described were designed from the viewpoint of simplicity, economy, and convenience, but departure from these conditions may be tolerated without detrimental effects.

The quantity of solvent water, time of reaction, pH of precipitation, and total time of precipitation may all be varied, somewhat, without any serious drop in product yield.

The rate of formation of EDDS-4H by the procedure described in Example I was determined by periodic isolation of product during the over-all reaction time. Table I below shows the quantity of product which approaches a maximum value:

6 TABLE I Percent Time of reaction (hrs): yield 1.5 55.1 3 67.9 5 71.8 8 76.2 24 85.1 32 87.2 48 89.7

When the yield of EDDS-4H is plotted against the log of the reaction time, a straight line is obtained. Extrapolation to 100% yield shows the obtaining of the theoretical yield after 155 hours of refluxing.

The true amphoteric nature of these polyamino polycarboxylic acids is shown by their ability to form salts with mineral acids.

EXAMPLE II Ethylenedz'amine Bis-N,N-Succinic Acid Dihydrochloride HeC 0 OH l [-CHslTl-CH-COOH] 2Cl- H HQC G OH 2 30 grams of ethylenediamine bis-N,N-succinic acid were added, with stirring, into 100 ml. of concentrated hydrochloric acid at room temperature to form a solution. After several minutes, a fine white crystalline precipitate separated out. The precipitate was filtered, washed with three, 25 ml. portions of acetone, and vacuum desiccated for several days. The yield was 28 g.

Analytical data.C H N O Cl -Percent N: Found 7.36; theory 7.67. Molecular weight determined by titration: Found 373; theory 365; inflections at pH of 5.5, 8.5 and 11.25.

Ethylenediamine bis-N,N-succinic acid may easily be converted to an ester as shown.

H CHzC O OH [*CHzAI-l H-C 0 01112 II CHaCO 0 01120113 [CHai I-CHCO O CHiCHs]:

A 146 g. (0.5 mole) sample of EDDS-4H in 400 m1. of ethanol was treated dropwise with g. of concentrated H SO The admixture was refluxed for 7 hours (a solution was formed after 4 hours). The clear liquor was diluted with ethanol, at 20 C., to 750 ml. and 168 g. (2 moles) of NaHCO were added thereto. The slurry was filtered and washed with ml. of ethanol. The combined liquor was again filtered with norite carbon and concentrated in vacuo at 80 C. The viscous, strawcolored syrup was soluble in water, alcohol, and acetone. The yield was 200 g. of crude product, which is 99% of theoretical yield of 202 g.

In addition to forming salts with acids, these amphoteric amino acids also form crystalline salts with suitable bases. The disodium dihydrogen salt forms a crystalline product; however, the tetrasodium salt is extremely soluble and hygroscopic.

EXAMPLE III Diethylenetriamine Bis-N,N"-Succinic Acid GH-CO ONa (111-0 0 0N3 Hi- C HaCTlaO H (excess) HiCOONfl a Ethylenediamine is only the first in a varied series of polyamines that yield insoluble adducts with maleic acid. Repeating the conditions of Example I, diethylenetriamine was substituted for ethylenediamine, as is described in the following example.

The reaction was carried out as described in Example I, combining 200 g. of maleic anhydride (2.02 moles) in 100 ml. of water with 320 g. of 50% by weight NaOH. This solution was then treated with 103 g. of diethylenetriamine (1.0 mole) and was refluxed for 48 hours. The reaction mixture had to be diluted to 800 ml. during the reflux period so as to keep the reactants and product in solution.

The reaction solution was cooled and then acidified with 320 m1. of concentrated HCl to a pH of 3.3. Upon setting overnight, the product, a fine white microcrystalline product, was filtered and washed with two, 100 m1. portions of Water. This material was dried at 100-105 C. to a white free-flowing powder. Yield: 180 g., 57% of theory (335 g.); M.P.: 208-210 C.

The sample of diethylenetriarnine bis-N,N"-suecinic acid was recrystallized in the normal manner, that is, by dissolving it first in NaOH solution, followed by reprecipitation in the cold at a pH of 3.3 with concentrated HCl. The resulting product was filtered and washed thoroughly with water. The product was divided into fraction (A) which was air dried to a constant weight and fraction (B) which was dried at 100 C. to a constant weight.

Analytical data.-

C12H21N303'H2O-M.W. determined titration: Found 358, theory 353. Percent N found: 11.72, theory 11.90.

(B) C H N O M.W. determined by pH titration: Found 340, theory 335. Percent N found: 12.49, theory 12.54.

EXAMPLE IV T etraethylenepentamine Bis-N,N -Succinic Acid H CHCOONa l A 2! HN(CH2CH2NCH2CH2NH2)Z HOOONa r t HN CH:CHzNCH:CH2NCHCOONa HzCOONa a l H The reaction was again carried out in the same manner described in Example I, that is, by combining 200 g. (2.04 mole) of maleic anhydride in 100 ml. of water with 320 g. of 50% by weight NaOH. The hot solution was treated with 189 g. (1.0 mole) of tetraethylenepentamine, and was then refluxed for 28 hours.

The final reaction solution was cooled, filtered, diluted to 1 liter and stored as a 1 molar solution of tetrasodium tetraethylenepentamine bis-N,N -succinate. Since acidification does not liberate the water soluble free acid, a 0.1 mole aliquot (100 m1.) of the tetrasodium salt was passed through a column of Amberlite lR-100 cation resin (acid form). The 800 m1. of acidic eflluent were concentrated under vacuo to a syrup, which was washed with ethanol and desiccated for several days until it Found EXAMPLE V J,6-Hexamelhylenediamine Bis-N,N'-Succz'nfc Acid o HC o 0 Na H [CHQCHICHZI:\TCH C O OH] 2 CHICOOH The reaction was carried out in the same manner as described in Example I, that is, by combining g. of maleic anhydride (1.02 moles) in 200 ml. of water with 160 g. of 50% by weight NaOH. The hot solution was then treated with 58 g. (0.5 mole) of 1,6-hexamethylenediaminc, and was refluxed for 48 hours.

The final liquor was cooled, and acidified with 160 ml. of concentrated HCl to a pH of 2.6. The white crystalline product was allowed to settle for several hours, and was then filtered and washed with 800 ml. of water. The crystals were dried to constant weight at C. The yield was 75 g., 64.6% of the theoretical yield of 116 g.

A 60 g. sample of the above product was dissolved in 10% NaOH, and reprecipitated by acidification to a pH of 2.6 with concentrated HCl. The product precipitated in two distinctly separate fractions.

The first crop (No. l) of crystals separated immediately from the acidified solution. This crop was collected, washed, and dried at 105 C. The yield was 10 g., 16.6% of theory.

A second crop (No. 2) of crystals separated from the clear filtrate upon standing for 15 minutes. The yield of dried product was 35 g., 58% of theory. This second crop was divided into two portions: (A) which was dried in air at room temperature, and (B) which was dried at 105 C. to a constant weight.

Analytical data of crop N0. 2.(2A) C H N O 2H OPercent N: Found 6.97; theory 7.11. (2B) C H N O -Percent N: Found 7.63; theory 7.82.

M.W. determined by pH titration: Found 328; theory 348. inflection pH was 7.0.

Crop No. 1 appeared to be the product formed by an impurity present in the 1,G-heXamethyIenediamine, namely, l-hydroxy-fi-aminohexane. This probably results from the following side reaction:

H CH-COONfl A l f- HO(CH2)sNH: HO(CH2)eNCH-COONa CH-COONa HnCOONa I HO(CH2)6NCHC0OH HtCOOH This by-product may be separated from the desired bisadduct by fractional crystallization as shown above.

9 EXAMPLE VI Dicflzylenetriamine Bis-N,N"-Tricarballylic Acid ClI-CO O'Iea 2 i C O OIea H20 0 Tea 174 grams of aconitic acid (1.0 mole) were treated with 40 ml. of water, followed by 450 of triethanol amine (3.0 moles) and, finally 51.5 g. of diethylenetriamine (0.5 mole). The thick mixture was then set aside to digest under gentle reflux at 125-130 C. for 36 hours.

The reaction solution, a dark red-brown syrup, was diluted to 1 liter and was used as a 0.5 molar solution of the product.

A 200 ml. (0.1 mole) aliquot of the reaction solution were treated with 24 g. (0.6 mole) of NaOH and 1 liter of ethanol. Prolonged stirring gave a thick oily sediment of hexasodium salt, which was washed free of triethanolamine with two 50 ml. portions of ethanol and was dissolved in 200 ml. of water. This solution was passed through a column of Amhcrlite IR100 cation exchange resin (acid form). The acidic etliuent was concentrated under vacuo to 65 ml., then treated with 800 ml. of ethanol. A brown solid separated, which was dried in a vacuum desiccator. The yield was 8 g., 21% of theoretical 33.8 g. yield. its decomposition point was approximately 230 C.

Analytical data.C H; N O Percent N: Found 10.91; theory 9.31. M.W. determined by pH titration: Found 447; theory 451. Infiections at pH of 6.8 and 10.5

The position of adduction of the primary amine to the unsaturation of aconitic acid may be either a or 5. Pos sibly the beta isomer may predominate.

EXAMPLE VII p-p'-Methylenedianiline Bis-N,N'-Succinic Acid H CHBCOOH l on @N-cH-coon MDDS The aryl amine incorporated into this reaction is water insoluble, as well as being insoluble in any alkaline aqueous media. Thus, triethanolamine was again used as both solvent and neutralizing base.

grams of maleic anhydride (1.02 moles) were added to 25 ml. of water and allowed to hydrolyze slowly to maleic acid. The mass of crystals were gradually dis solved in 330 g. (2.2 moles) of triethanolamine. Finally, 99 g. (0.5 mole) of p.p'-rnethylenedianiline were added and the reaction mixture digested under reflux at C. for 26 hours. The reaction solution remained as one clear phase.

The solution was cooled and diluted with 250 ml. of water. Since the reaction solution remains as one phase, this is evidence that the amine has reacted, otherwise it would have separated on dilution.

The diluted solution was acidified with 183 ml. of concentrated HCl (2.2 moles). A gray oil separated immediately and was decanted free of the mother liquor. This residue was washed with 200 ml. of water, dissolved in 280 ml. of water containing 80 g. (2.0 moles) of NaOH, and reprecipitated with 166 ml. of concentrated HCl (2.0 moles). The residue was again decanted free of mother liquor, washed with three 200 ml. portions of water and two ml. portions of ethanol. The free acid solidified when desiccated; however, the surfaces turned red when exposed to air, evidencing oxidation. The yield was 150 g., 70% of the theoretical 215 g. yield.

EXAMPLE VIII Diplzeny Imethane p,p'-Di-N-Pyrraliaone-ZA- Carboxylic Acid 120 grams of itaconic acid (0.92 mole) were added to 10 ml. of water, and the resulting salt was treated with 300 g. of triethanolamine (2.0 moles). The slurry was heated and stirred until completely dissolved. The resultant viscous solution was treated with 91 g. of p,p'- methylenedianiline (0.46 mole) and digested under gentle reflux at 120-130 C. for 48 hours. The reaction mixture, which contained some insolubles, was diluted to 600 ml., and filtered through a pad of diatomaceous earth. The clear filtrate was then acidified with ml. of concentrated HCl. The oil, which separated, was decanted free of mother liquor, washed with two 100 ml. portions of water, and was then redissolved in 250 ml. of water containing 80 g. (2.0 moles) of NaOH. The product was repreeipitated with 165 ml. of concentrated I-ICl (2.0 moles), washed with two 100 ml. portions of water, and was then dried in a vacuum desiccator for several days. The final product was a dark-brown crystalline mass. The yield was 40 g., 21% of the theoretical 194 g. yield. The melting point was 200-210 C.

Analytical data.C H N O Percent N: Found 6.92; theory 6.64. M.W. determined by pH titration: Found 458; theory 422. Infiections at pH of 9.0.

1 1 EXAMPLE 1x Ethylenediamine Bis-N,N'-2-Hydr0xyethyl Bis- N,N'-Succinic Acid (EDDSDE) CHnCOONa [*CHzlT- H-COONt1 +2ClCHaCHzOH-I-2NaOH CHzCO ONa [-CHgN HCOONtL +2NaCl HzCHzOH 292 g. (1.0 mole) of ethylenediamine bis-N,N-succinic acid were added to 250 ml. of water containing 320 g. of 50% by weight NaOH (4.0 moles). The solution was stirred at 60-70 C. and was treated dropwise with 161 g. of chlorohydrin (2 moles) and also 160 g. of 50% NaOH (2 moles) while maintaining a solution that was alkaline to pHydrion paper (pH of 11-12). Upon the completion of this addition (Va-1 hour), the reaction temperature was raised to boiling for minutes, cooled, and

acidified to a pH of 2.0 with 320' ml. of cone. HCl. The liquor was filtered, seeded with product crystals, and stirred occasionally for 48 hours. The white fluffy product was filtered, washed with 100 ml. of water and dried in air to a constant weight. A yield of 260 g. was obtained, 68.4% of the theoretical 380 g. yield. The prodnot had a M.P. of 168.5469 C. (:1).

An alternate name for this product is ethylenediamine bis-N,N'-ethanol-bis-N,N-succinic acid.

EXAMPLE X Ethyleucdiamine Bis-N,N'-2-Hydr0x3-'ethyl Bis-N,N'- Succz'nic Acid 292 g. (1.0 mole) of ethylenediamine bis-N,N'-succinic acid were dissolved in 400 ml. of water containing 320 g. of 50% by weight NaOH (4.0 moles). The solution was stirred at 55 C. and was treated dropwise with 190 g. of chlorohydrin (2% moles), while maintaining the pH at 10.5 with the aid of a pH meter. Upon completion of the addition (one hour) and one hour of digestion at 55 C., the reaction solution was cooled to C., and was acidified with 330 ml. of concentrated HCl to a pH of 2.0. The liquor was seeded with the product crystals, and was stirred occasionally for 3 days. The white fluify product was filtered, washed with 200 m1. of water, washed with 100 ml. of ethanol, and was then oven dried at 90 C. to a constant weight. A yield of 240 g. was obtained. At the end of seven weeks, the total product recovered increased to a. yield of 290 g., 80.1% of the theoretical yield of 362 g. (monolactone).

When the above referred to white fiuify product is initially precipitated, it is in the form of the free acid. However, when this crystalline tetra-acid is dried in an oven at approximately 90 C., the acid is dehydrated to a monolactone, as follows:

Further drying of the monolactone up to 125 C. does not result in any further loss in weight, thus indicating GHzCO OH that the preparation of a dilactone requires more severe conditions. The presence of the lactone structure may be evidenced by the test described in Spot Tests," F. Feigl (Elsevier, 1939), pages 295-297. This test procedure gives a positive test with the lactone shown in the above formula. When a pH titration of the lactone reaches a pH of 10, there is a downward shift in pH which can be attributed to the slow hydrolysis of the lactone and liberation of free carboxyl groups. The physical characteristics of the lactone do not differ from those of the free acid in any noticeable respect.

EXAMPLE XI Erhylenediamine Bis-N,N'-2-Hydroxyethyl Bis-N,N- Succim'c Acid CHzCOONu. [-CHr-N-CH-COONn] 2C1CHzCH2OH NaaGO o OH2COONa [-CH2N-CHCOONa:| QNaCl HzCHgOH 2 272 g. (1.0 mole) of ethylenediarnine bis-N,N'-succinic acid were slowly added to 500 ml. of water containing 496 g. of sodium carbonate monohydrate (4.0 moles). The solution was stirred at 65 C. and treated dropwise with 160 g. of chlorohydrin (2.0 moles) over a one hour period. Upon completion of the addition, the solution was warmed slowly while stirring to C., was cooled, and was slowly acidified to a pH of 2.0 with 450 ml. of concentrated HCl. The slurry was filtered and the filtrate seeded with product crustals. The mixture was stirred occasionally for several hours and was set aside for 24 hours. The white product was filtered, washed with ml. of Water, washed with 100 ml. of ethanol, and then dried at 90 C. to a constant weight. A yield of g. was obtained, 33% of the theoretical yield of 362 g. (monolactone).

The typical analysis for the free acid, and the mono lactone of Example X are tabulated below.

Total N dererminalion.-EDDSDE mono-lactone- C H N O Percent N: Found 7.68; theory 7.73. EDDSDE free acidC H N O Percent N: found 7.16; theory 7.37.

Titration dam-Monolactone M. wt: Found 359.5; theory 362. Inflections at pH values of 10.30, 7.25. Free acidM. wt.: Found 381; theory 380. Inflections at pH values of 10.30, 7.25 (4th and 3rd COOH).

Solubility data. Monolactone-0.382 g./100 ml. H O at 27 C. Free acid-0.303 g./l00 ml. H O at 27 C.

The free acid and monolactone are insoluble in alcohol, acetone, dioxane, dimethyl formamide, diethylene glycol, and many common organic solvents.

The free acid may lactonize in boiling water systems; however, the sodium salt may be boiled in solution for several days with no noticeable effect. The free acid may be isolated by drying the product crystals in air without the application of heat.

The following example describes the substitution of ethylene oxide for chlorohydrin.

EXAMPLE XII Ethylenediamine Bis-N,N'-2-Hydroxyethyl Bis-NW- Succinic Acid 292 g. of ethylenediamine bis N,N'-succinic acid were Dissolved in NnOH, then back titrated with 1101.

dissolved in 300 ml. of water containing 320 g. of 50% by weight NaOH (4.0 moles). The solution was diluted to 1 liter, permitted to set, the pH was adjusted to 10.6, and the solution was heated to 60-65" C. While agitating and maintaining this temperature, a fine stream of ethylene oxide gas was introduced through a perforated polyethylene tube. When the reaction was complete after 2 hours, the solution was warmed to 95 C., cooled to room temperature, and acidified to a pH of 2.0 with 300 ml. of concentrated HCl. The reaction solution was seeded with product crystals, occasionally stirred, and the pH of the solution was left undisturbed for 72 hours at room temperature. The product was filtered, washed with 200 ml. of water, washed with 100 ml. of ethanol, and dried at 100 C. to form the dry monolactone product. A yield of 255 g. (M.P. 168l70 C. (d)) was obtained, 70.4% of the theoretical yield of .362 g. (monolactone).

Ethylencdiamine bis-N,N'-2-hydroxyethyl bis N,N'- succinic acid forms a crystalline tetrasodium salt, in the form of a decahydrate.

Bis-N,N'-Succinate Decahydrate CHaC O OH J: (HOH) C Hz-N- 11-0 0H HaCHeOH KIZHzCO ONa -CHzN--CHCOONu -H2 HzCHzO H I .181 g. (0.5 mole) of ethylenediamine bis-N,N-2-hydroxyethyl bis-N,N'-succinic acid (monolactone) were stirred into 160 g. of 50% by weight NaOH (2 moles). The temperature was kept below 60-70 C., and, finally, 50 ml. of water were added. The Warm solution was seeded with several large crystals and was allowed to cool.

At the end of 24 hours, the undisturbed liquor produced large well-formed transparent crystals. These were broken up, filtered, and air-dried cautiously to the decahydrate. A yield of 221 g. was obtained, 68.2% of the theoretical yield of 324 g. The saturated mother liquor was 32.5 B. at 27 C.

A slurry of granular crystals rather than large lumps may be obtained by stirring the warm liquor after seeding, and then cooling slowly the liquor for several hours. The resulting crystals are uniform in size, similar to granular sugar.

If it is desired to dry the decahydrate to the anhydrous form, it must be done with care since the decahydrate easily melts at 90 C. to a non-crystallizing syrup. The crystalline hydrate may be placed in an oven and the temperature raised slowly from 30 C. to 100 C. over a 24 hour period (thin beds of material dry most efficiently).

A typical analysis of the tetrasodium ethylenediamine bis-N,N-2-hydroxyethyl bis-N,N-succinate, hydrate and anhydrous product follows:

Decahydrate.-C H N O Na -10H OPercent N: Found 4.15, theory 4.32%. Titration data-Mol. Wt.: Found 654, theory 648. inflections at pH values of 10.75, 7.15.

Anhydr0us.C l-I N O Na Percent N: Found 5.98, theory 5.98%. Titration dataMol. Wt.: Found 481, theory 468. Inflections at pH values of 10.75, 7.15.

Drying tests of the decahydrate resulted in a 27.23 loss of water, compared to a theoretical loss of 27.77%.

The insoluble dibariurn salt was prepared in the next example.

14 EXAMPLE XIV Dibarium Ethylenediamine Bis-MN'-2-Hydr0xyethyl Bis-N,N'-Succilmte HsCHzOH CHaCOD HsCHsOH z 36 g. (0.1 mole) of ethylenediamine bis-N,N'-2-hydroxyethyl bis-N,N'-succinic acid (monolactone) were added to 100 ml. of water. 200 ml. of 1.0 molar BaCl solution were then added. The slurry was stirred, and treated with 32 g. of 50% by weight NaOH (0.4 mole). The slightly soluble product soon crystallized-out, and was filtered, was washed with 50 ml. of hot water, was washed with 50 ml. of ethanol, and was then dried at 120 C. to a constant weight. A yield of 45 g. Was obtained, of the theoretical yield of 65 g.

Analytical data.--C H N O ,Ba -Percent 4.15, theory 4.30%.

The dibarium salt may also be easily prepared by adding BaCl solution to a solution of the tetrasodium salt of the above compound.

EXAMPLE XV Lead Dihydrogen Ethyleuediamine Bis-N,N-2- Hydroxyetlzyl Bis-N,N-Succinare CHaCOOH [-CHz-N( IIICOOH] Pb(OOC-CHt n v CHiCHaO t QNaCl N: Found 37.9 g. (0.1 mole) of lead acetate trihydrate were dissolved in 200 ml. of water, and the solution was treated with 36.2 g. of ethylenediamine-bis-N,N'-ethanol bis- N,N-succinic acid (0.1 mole as monolactone) with stirring. After stirring for a few hours, the mixture solidified. The product was added to 1 liter of boiling water and filtered. The filtrate, on cooling, yielded a crop of crystals which were recrystallized from boiling water (1 liter). The product was dried under vacuo at 100 C. The product was slightly soluble in water and was very soluble in alkaline solutions.

Analytical dara.-C H N O Pb-Percent N: Found 4.83, theory 4.79%.

A slight variation in the procedure made it possible to isolate the more soluble zinc chelate.

EXAMPLE XVI Zinc Dihydrogen Ezhylenca'iamine Bis-N,N'-2- Hydroxyetliyl Bis-N,N-Succinare 22 g. of (0.1 mole) of zinc acetate dihydrate were dissolved in 200 ml. of water. 36.2 g. of ethylenediamine bis-N,N-ethanol bis-N,N-succinic acid (0.1 mole as monolnctone) were then added. The admixture was stirred and a nearly clear solution was formed. The solution was filtered and concentrated by boiling it in vacuo to 50 ml. The addition of ethanol precipitated a solid which was filtered, dissolved in 40 ml. of hot water, cooled, and reprecipitated with ethanol. The white semig. (0.1 mole) of copper acetate monohydrate were dissolved in 1.5 l. of water. 36.2 g. of ethylenediamine bis-N,N'-ethanol-bis-N,N'-succinic acid (0.1 mole as monolactone) were then added. The suspension was boiled to dissolve all solids, filtered hot, and then cooled. The solution yielded a crop of fine blue crystals (a second crop may be obtained by treating the mother liquor). The product was dried in a vacuum oven at 80 C. to a constant weight.

Analytical data.C H N O CI.1Percent N: Found 6.31, theory 6.20%.

The ferric chelate is very soluble; however, it was prepared in the following example.

EXAMPLE XVIII Ferric Hydrogen Ethylenediamine Bis-N,N-2-Hydroxyethyl Bis-N,N-Succinate 19.5 g. (0.1 mole) of 98% assay basic ferric acetate were added to a slurry of 36.2 g. of ethylenediamine bis- N,N'-ethanol bis-N,N-succinic acid (0.1 mole as monolactone) in 100 ml. of water. The mixture was stirred until it was dissolved and was then filtered through diatomaceous earth. When the clear liquid Was treated with 400 ml. of ethanol, a green-yellow solid depositedout on standing. The product was filtered out, washed with ml. of ethanol, and dried under vacuo at C. to a constant weight. A yield of 26 g. was obtained, 59% of the theoretical yield of 44 g.

Analytical data.-C, H N O FePercent N: Found 6.10, theory 6.47%. Percent ash: Found 21.40, theory as F6203.

EXAMPLE XIX Diet/1 ylenetriamine T rz's-N,N ,N -2-H ydroxyethyl Bis- N,N"-Succinic Acid (DTHDS) CHaCOONa HN -CHgCHzN HCOONa +3CHn-CH2 CHzCOONa oxide gas was introduced.

When the reaction was completed, the reaction liquor 16 was warmed to C., filtered, cooled, diluted to 1 liter, and stored as a 0.5 molar solution of tetrasodium diethylenetriamine tris-N,N,N"-2-hydroxyethyl bis-N,N'-succitrate.

EXAMPLE XX Tetraethylenepemamine Penta-N,N',N",N',N""-2-Hydroxyethyl Bls-N,N""-Succinic Acid (TPHDS) CHICOONG IIN CH2CH1NCHaCH2N- H-COONa +5CEQ-7CH: f

CHaCOONa (5H HaOH 179 g. (0.5 mole) of tetraethylenepentamine bis-N, N""-succinic acid were dissolved in 500 ml. of H 0 containing 160 g. of 50% NaOH (2.0 moles). The solution was stirred, warmed to 60 C. and its pH adjusted to 11.0. While maintaining these conditions, a fine stream of ethylene oxide gas was introduced.

When the reaction was completed, the reaction liquor was warmed to 90 C., cooled, filtered, diluted to 1 liter, and stored as a 0.5 molar solution of tetrasodium tetraethylenepentamine penta N,N',N",N"',N"" 2 hydroxyethyl-bis-N,N'-succinate.

EXAMPLE XXI Tetracthylcnepentamine Penta N,N',N",N",N"" Z-Hydroxyethyl Bis N,N"" Succinic Acid, Penta Hydrochloride CH COONB CHr-N CH;OH NCH1OHzNJJHCOONa +5110] I Ha HrCHrOH )H CHSOH 2 CHICOOH GHQ-N CH:CHINCHICHQNCHCOOH @1161 OH: H: JI'HCHQOH H CHzOH 2 ml. aliquot of a 0.5 molar solution of tetrasodium tetraethylenepentamine penta N,N',N",N",N""-2-hydroxyethyl bis-N,N""-succinate (0.05 mole) were passed through a column of Amberlite IR-lOOC cation exchange resin (acid form) to remove sodium ions. The effluent of free acid was then treated with 21 ml. of conc. HCl (0.25 mole), concentrated in vacuo to 60 ml., and then added in a cold state to 400 ml. of acetone. The residue was washed twice with 100 ml. of acetone, and the resulting solid was dried under vacuo at 70 C. to a constant weight. A yield of 25 g. was obtained, 61% of the theoretical yield of 41 g.

Analytical data.--C H N O Cl -Perccnt N: Found 8.39, theory 8.52%.

The 2,3 propylene-glycol radical, which is more hydrophylic than ethanol, may be introduced by means of lchloro 2,3-propanediol or by reaction with epichlorohydrin.

EXAMPLE XXII Tetrasodium Ethylenediamine Bis-N,N-2,3-Dihydr0xypropane Bis-N,N'-Succinale (EDPDDS") CH2CO0N8 [-om-N n-o 001%] zotonlononion 2mm:

OHiCOONa CH:N n ooona upon-on,

292 g. (1.0 mole) of ethylenediamine bis-N,N'-succinic acid were dissolved in 500 ml. of water containing 320 g. of 50% by weight NaOH. The solution was adjusted to a pH of 10.75, warmed to 60 C., and stirred vigorously. A total of 221 g. (2.0 moles) of l-chloro-2,3-propanediol and 160 g. (2.0 moles) of 50% NaOH were added drop wise into and blended with the agitated solution. During the addition, the pH and temperature were maintained at their original values. After V2 hour, the reaction solution was cooled, filtered, diluted to 2 liters, and stored as a 0.5 molar solution of tetrasodium ethylenediamine bis- N,N-2,3-propanedio1 bis-N,N-succinate.

The solution did not cause precipitation of any product upon acidification with HCl to a pH of 2.0. Concentration of the acidified reaction mixture results in the formation of viscous hygroscopic syrups that are contaminated with NaCl.

Concentration of the original alkaline reaction liquor containing tetrasodium salt results in a gelatinous sludge which resists solidification or crystallization.

The incorporation of the propylene-2,3-diol group to ethylenediamine bis-N,N'-succinic acid was also achieved by the use of glycidol.

EXAMPLE XXIII Ethylenediamine Bis-N,N'-2,3-Dihydroxypropane Bis-N,N'-Succinic Acid GHiC O ONa -oInN- H-COONa 20H, orr-ornon ---s l H 2 O CIIECOON CH -N H-COONB.

Hz-CK-CH:

OH H 2 73 g. (0.25 mole) of ethylenediamine bis-N,N'-succinic acid were dissolved in 100 ml. of water containing 80 g. of 50% NaOH (1.0 mole). The pH was adjusted to 10.50. 37 g. (0.5 mole) of glycidol were added dropwise to the agitated solution. The temperature rose from 30 C. to 48 C. The liquor was set aside for 16 hours. It was warmed to 90 C. and cooled to room temperature. This solution of tetrasodium salt was passed through a cation exchange column of an acid form. The acidic efiiuent was concentrated in vacuo to 150 ml. This was further concentrated over calcium chloride in a vacuum desiccator. The product remained as a viscous oil after 6 weeks. Cooling and treatment with solvents such as acetone or ethanol does not solidify or crystallize the hygroscopic residue.

EXAMPLE XXIV Di barium Ethylenediamine Bis-N,N'-2,3-Dz'hydr0xypropane Bis-N,N'-Succinate 01120 0 Na CH2NJ3HO O ONa CH: CH- OH:

CHQOOO A 200 ml. aliquot (0.1 mole) solution of 0.5 molar tetrasodium ethylenediamine bis-N,N-2,3-dihydroxypropane bis-N,N-succinate was treated with 55 g. (0.2 mole) of barium acetate monohydrate. The solution was stirred until nearly clear, filtered, treated with 400 ml. of ethanol, and then stirred for /2 hour. The product was filtered dry, dissolved in 150 ml. of water, and reprecipitated with 400 ml. of ethanol. The white slurry was filtered and dried under vacuo at C. to a constant weight. A yield of 64 g. was obtained, of the theoretical yield of 71 g.

Analytical data.C H N O Ba -Pereent N: Found 3.62, theory 3.93%. Percent ash: Found 56.17, theory 55.54% as BaCO Percent Ba: Found 39.85, theory 39.78%.

EXAMPLE XXV 1,S-Hexamethylenediamine Bis-N,N'-2,3-Dihydroxypropane Bis-N,N'-Succinic Acid (HDHPDS) OHzCOONa 70 g. (0.2 mole) of hexamethylenediamine bis-N,N'-

EXAMPLE XXVI Ethylenedz'amine Bis-MN-3-Hydroxypropane Bis- N,N-Succinic Acid (EHPDS) CIIZCOOH 75 g. (0.25 mole) of ethylenediamine bis-N-N'-succinic 7 acid were dissolved in ml. of water containing 80 g. of 50% NaOH (1.0 mole). The solution was refluxed gently while 52 g. of l-chloro 3-propanol (0.5 mole) were added dropwise thereto. In the meantime, the solution was maintained at a pH of 10.5-11.0 to Nile blue by the portion-Wise addition of a total of 100 g. of 25% by weight NaOH. When the reaction was complete, the mixture was digested for /2 hour, cooled, and acidified with 85 ml. of concentrated HCl (1.0 mole) to a pH of- 2.0. The product was allowed to settle overnight, was then filtered, washed with 50 ml. of water, washed with 50 ml. of ethanol, and was air-dried to a constant weight. A yield of 28 g. was obtained, 29% of the theoretical yield of 96 g.

Analytical data.C H N O Percent N: Found 7.11, theory 6.86%.

vTim:tion.---lvlol. wt.: Found 339, theory 409. Inflections at pH values of 5.5, 8.5, 11.25.

1 9 EXAMPLE xxvn Ethylenediamine Bis-N,N'-Tetraglyc0l Bis-MN- Succz'nic Acid (EDTGDS) H: C H2O} i (Teo=Tr-iethanolamlne) 292 g. (1.0 mole) of ethylenediamine bis-N,N'-succinic acid were added to 900 g. of triethanolamine (6 moles) containing 100 g. of water. The thick slurry was warmed on an oil bath and gently refluxed to a clear liquid. Over a 3 hour period, 420 g. (2 moles) of polyglycol chloride (#210, Union Carbide Chemical Co.) were added. Heating was continued for 8 hours.

The resulting thick brown liquid was cooled to room temperature, diluted with 2 liters of ethanol and 330 ml. of concentrated HCl. The slurry was cooled to 5 C., filtered, and washed with 500 m1. of ethanol. The mother liquor was boiled free of ethanol while maintaining a 2 liter volume with water. The product exhibited great surface-active properties.

The solution was cooled, adjusted to 2.0 liters with water and was stored as a 0.5 molar solution of ethylenediarnine bis-N,N'-tetraglycol bis-N,N-succinic acid. It was identified in the form of an insoluble zinc salt.

EXAMPLE XXVIII Dizz'nc Ethylenedz'amine Bis-N,N-Tetraglycol Bis-N,N'-Succinate HzCHsOhH EXAMPLE XXIX Ethylenediamine Bis-N,N'-2-Hydr0xy-2-Phenylethane Bis-N,N'-Succinic Acid (EDPEDS") H CHzCOONB [-orrrz r-on-ooona] 2on om CHaCOONa 146 g. (0.5 mole) of ethylenediamine bis-N,N'-succinic acid were dissolved in 500 ml. of water containing 160 g. of 50% by weight NaOH (2.0 moles). The solution (pH of 11.0) was warmed to 70 C., and then, while vigorously stirring, was treated by the dropwise addition of 120 g. of styrene oxide (1 mole). When all the epoxide dissolved, the solution was digested at 95 C. for 1 hour, cooled to room temperature, and was extracted with 100 ml. of ether. The aqueous yellow liquor was diluted with water to 1 liter and after 1 week was decanted to remove insolubles. The clear liquor represents an 0.5 molar solution of the tetrasodium salt of ethylenediamine bis-N,N'-2-hydroxy Z-phenylethane bis-N,N-succinic acid.

A 200 ml. aliquot (0.1 mole) solution was acidified with 35 ml. (0.4 mole) of concentrated HCl. The adduct separated as a yellow oil. It was Washed with 1 liter of water. It was then dried in a vacuum oven at C. to a constant weight. A mass foamed, which hardened to a hygroscopic brittle mass. First crop: 34 g. yield, 72% of the theoretical 47 g. yield.

Analytical data.C H N O Percent N: Found 5.07, theory 5.26%.

Titrati0n.-Mol. wt.: Found 564, theory 532. Inflection at a pH of 10.70.

EXAMPLE XXX Ethylenediamine Bis-N,N'-3-Phen0xy Z-Hydroxypropane Bis-N,N-Succinic Acid (EDPHPDS) 146 g. (0.5 mole) of ethylenediamine bis-N,N-succinic acid were dissolved in 500 ml. of Water containing 160 g. of 50% by weight NaOH (2.0 moles). The solution (pH of 11.0) was warmed to 70 C., then, while stirring rapidly, was treated by the dropwise addition of 150 g. of glycidol phenyl ether (1.0 mole). When all the epoxide had dissolved, the solution was digested at C. for 1 hour, cooled to room temperature, and extracted with ml. of ether. The resulting clear liquor was diluted to 1 liter, and, after several days, decanted free of insolubles. This clear liquor represented a 0.5 molar solution of the tetrasodium salt of ethylencdiamine bis-N,N'-3-phenoxy Z-hydroxypro-pane bis-N,N'-succinic acid.

A 300 ml. aliquot solution of the reaction liquor (0.15 mole) was acidified with 50 ml. of concentrated HCl (0.6 mole). A white syrup separated-out. The syrup was washed with 1 liter of water and was dried under vacuo at 90 C. to a constant weight. The product foamed, then hardened to a hygroscopic brittle mass. A yield of 45 g. was obtained, 83% of the theoretical yield of 54 g.

Analytical data.C H N O -Percent N: Found 4.71, theory 4.73%.

Titration.-Mol. wt.: Found 616, theory 592. Inflection at a pH of 10.60.

21 EXAMPLE XXXI Ethylenediamine Bis-NJW-Succinic Bis-N,N'-Acetic Acid (EDDSDA") onioooNu 5 A: -oHiN-i:H-oooNa zolorrzooom +2 NaOH-- CH*N HTCOOM 43801 146 g. (0.5 mole) of ethylenediamine bis-N,N'-succinic acid were dissolved in 200 ml. of water containing 160 g. of 50% NaOH (2.0 moles). The solution was stirred and was heated in a beaker to 50 C. 100 g. (1.06 mole) of chloroacetic acid were slowly added to the solution along with 160 g. of 50% NaOH while maintaining the pH at 10.5-11.0 (Bogens indicator). The temperature of the reaction solution rose to 100 C. (cooling may be required to prevent the reaction mixture from boiling out of the vessel). when the reaction was complete, the solution was cooled and acidified to a pH of 1.5 with 240 ml. of concentrated HCl. The product separated-out overnight, was filtered, was washed with 50 ml. of water, and was dried below 80 C. to a constant Weight. A yield of 140 g. was obtained (M.P. 2l2-218 C.), 70% of the theoretical yield of 202 g. (as dihydrate).

Drying the dihydrate at 80 C. or more causes decomposition, and drying in vacuo below 80 C. removes the theoretical amount of hydrated water.

The product, a white crystalline solid, was slightly soluble in water, soluble in strong aqueous acids and alkalies, but insoluble in acetone, alcohol, benzene and many common organic solvents. It sequester in alkaline solutions calcium, magnesium, copper, etc.

Analytical data. C H N O -ZH O Percent N: Found 6.28, theory 6.31%.

Titratin.-Mol. wt.: Found 448, theory 444. Inflection at pH values of 5.75, 8.5, 11.0 (4th, 5th and 6th COOH groups).

EXAMPLE XXXII Octasodium Ethylenediamine Bis-N,N'-Methanephosphonate Bis-N,N'-Succinale (EDMPDS) HaP OgNfM 292 g. (1.0 mole) of ethylenediamine bis-N,N'-succinic acid were dissolved in 500 ml. of water containing 320 g. of 50% NaOH (4.0 moles). The solution was then treated with 308 g. of 84% chloromethanephosphonic acid (2.0 moles), and 320 g. of 50% NaOH (4.0 moles). The reaction solution was refluxed in a stainless steel container while the pH was kept at 11.0-11.5 (pI-lydrion paper); 160 g. of 50% NaOH were consumed. The total reflux time was 24 hours.

When an aliquot of reaction solution was acidified to a pH of 1.5 with concentrated HCl, it did not yield the solid free acid; similar results were obtained when the solution was further treated with acetone or ethanol. Concentration of the alkaline reaction liquor yields a mushy slurry which does not solidify or crystallize. Since neither the free acid nor sodium salt was isolated, identification was carried out with an insoluble salt thereof.

2 EXAMPLE xxxnr Tetmbarium Ethylenediamine Bis-N,N'-Methaneph0spizonate Bis-N,N-Succinate C H10 0 O Na (JEEP OsNB! I CHiCO 0 Ba --CHg-NCH-COO SNaCl H2PO3B8 A 200 ml. aliquot solution of octasodiurn salt (0.1 mole) was added to 600 ml. of water. 400 ml. of 1.0 molar BaCl solution were then added while stirring the solution. The slurry was stirred for 1 hour, filtered, washed with ml. of water, washed with 100 ml. of ethanol, and was then dried at -420 C. for 5 hours. A yield of 76 g. was obtained, 75% of the theoretical yield of 102 g.

Analytical data. C H N O P Ba Percent N: Found 2.55, theory 2.68%. Percent Ba: Found 51.5, theory 53.7%.

EXAMPLE XXIGV Meta-Dixylyl-oc,ni'-Diamine Bis-N,N'-Succinic Bis-N,N'- Acetic Acid (XDADS) mCooH CHzCOONt-l OHr-N- HCOONB HICOONI) OHzCOONa Hs-N- H-COONB HzCOONu 184 g. (0.5 mole) of m-dixylyl-a,m'-diamine bis-N,N'- succinic acid were dissolved in 200 ml. of water containing g. of 50% by weight NaOH. The pH was kept at 11.0 while the temperature was raised to 80 C. 100 g. (1.05 moles) of chloracetic acid and g. of 50% NaOH were slowly added to and blended with the solution while maintaining a maximum temperature of 95 C. by cooling the reaction mixture. The resulting liquor was digested at 95 C. for /2 hour, was cooled, and diluted to 1 liter. This solution contained 0.5 molar hexasodium m-dixylyl 0:,a' diamine bis N,N'-diaceticbis N,N'disuccinate.

EXAMPLE XXXV Our products are exceptional chelants or chelating agents, as evidenced by the data shown in Table II, infra. Table II shows instances in which effective chelation was observed when 0.001 mole of metal ions were treated with from 0.001 to 0.002 mole of specified chelant in 50 ml. of water at the designated pH. Excess chelant is used to compensate for the use of products that may have a purity of less than 100%. A trace (e.g. 1-2 drops of saturated Na i-IP0 solution) of orthophosphate was added to induce precipitation where the chelating action was weak. The chelates have a mole ratio of chelant to metal ion of 1:1.

The symbol in Table II indicates positive chelation, which is evidenced by the lack of normal precipitation under the specified conditions. The i" symbol designates that a precipitate forms after several hours. The pH values of the various test solutions are designated at the bottom of Table II.

TABLE II METAL IONS Chelant Example A1+++ Ce++++ (1 0+ Q F pi t-t 12 3+ C 1+ Q M 1 b++ Th++ Th++++ Zr-H- Z1-++++ Z EDDSDE IX 1 i i DIHDS XIX TPHDS XX EDPDDS XXII EHPDS... HDHPDS .5. names" a EDDSDA i 1- EDPEDS EDPHPDS XXX EDTGDS. XXVII XDADS XXxIv. pH(11n]essa lsindieated) 3.5 10.5 11.0 5.25 11.0 11.0 10.5 11.0 10.5 10.5 10.5 10.5 14.0 10.5 14.0 10.5 pH (where a is indicated) *13. 0 *120 *1 23 *12.0

i NOTE.-+ equals positive ehclation, :l: equals precipitate [arms after several hours. The ability of the above products shown in Table II, TABLE IV above, to form stable water-soluble chelates with multim m m n 01m valent metal ions has been well established. This propg erty along with others makes these compounds particuweight larly suitable for such fields as water treatment, metal Compound ample Comment cleaning and treatment, antioxidants, dyeing and textile treatment, rubber and res1n formulation, petroleum re fin- EDDSDD a 56% Clean 51mm, mg, mineral recovery and purification, pharmaceutical DTI'IDS 0.51121 1:10.:

. 1 uses, analytical uses, agricultural uses, and radio-decon- 323 38 g3; tamination, and many others. 11 DHPDS 0. 4300 Light rust.

Ell PDQ 0. 1450 I] envy rust. EXAMPLE XXXVI Flrruos: 0. 2300 De. 1 asses... .L3 0. The products of this inventionwere found to be quite EDDSDL" 0,5370 clean Surface) effective in removing rust and oxide coatings from metal EDMPDS 05330 no} surfaces in aqueous solutions having a pH below 9.0 and XDADS XXXW 04020 containing a reducing agent such as sulfite, thiosulfate, sugar, hydroquinone, etc. For example, fresh uniformly rusted iron strips having a 81.6 cm. surface were immersed for three hours at 75 C. without agitation in a cleaning solution having the following formulation:

EDDSDE (Example IX) g 10 Sodium bisulfite (58.5% S0 g 5 Water was added to bring the volume to 200 ml.

pH (adjusted with NaOH) 8.0

Table III, infra, shows the weight of rust removed from the 81.6 sq. cm. surface of the test strip along with the condition of the surface.

At a pH of 8.0, much of the rust was removed by flaking, and left insoluble particles suspended in the cleaning bath.

The next, a second, series of tests were conducted in same manner, except the test solutions were adjusted to a pH of 7.0 instead of pH 8.0. The results of these tests are shown in Table IV, infra. The asterisks in Table IV indicate that rust was completely dissolved, resulting in a clear bath and clean metal surface.

Cit

Rust was completely dissolved, resulting in a clear bath and clean metal surface.

A comparison of Tables III and IV shows that the pH of 7.0 was more effective than 8.0 for the efiicient rust removal and maintenance of bath clarity.

EXAMPLE XXXVII The products of our invention were found to inhibit mineral acid attack on plain iron. While most of the compounds were moderately effective, two members (see Examples XXIX and XXX) were particularly outstanding. The acid used was 704 g. or 500 ml. of by EXAMPLE XXXVIII Formulations of urea-formaldehyde in water were found to set" shortly after 34 hours. The addition of a small quantity of EDDSDE and the like supppressed this solidification. Typical formulation are shown as Samples I-III, infra:

SampleI ml. of formalin 68 g. of urea pH of 7.5

25 Sample II Sample I plus 15 g. of EDDSDE (Example IX) Sample III Sample I plus 15 g. of EDPDDS (Example XXII) The compounds of this invention may be used to hold the metal in electrolytic plating or strike baths. The plating ions (chelated) deposit on higher metals. The replaced metal is inturn taken up by the chelant.

A typical bath was made up as follows:

CuSO -5H O g 32 EDDSDE (Example IX) g 100 Wetting agent g. 0.5 pH (adjusted with NaOl-I) 5.0 Temperature .C 50

A clean strip of iron, 225 sq. cm. surface area, was immersed in the above bath for 15 minutes. An adherent, even coating of copper was formed. It was found to weight 0.0246 g. and have a 1.226 X l cm. thickness.

EXAMPLE XXXX Plants growing in chlorosis producing calcareous soils were found to respond rapidly to treatment with EDDSDE-FeNa. A sample preparation of the ferric chelate follows:

EDDSDE 362 g. (as monolactone). H O 500 ml. NaOH, 50% 320 g.

The above ingredients were mixed, cooled to room temperature, and, while stirring rapidly, 333 ml. of 1.5 molar Fe (S0 were added. The red-brown liquor was cooled to 0 C., decanted free of Na SO -H O, and used as such.

Tests showed that the application of 50-125 p.p.m. Fe to soil having red kidney bean plants growing therein, resulted in the greening of the plants and at least in part caused the soil to yield a good crop of beans. (There were good results with 50 p.p.m. Fe and no signs of toxicity with 125 p.p.m. Fe.) Untreated plants (control) were yellow or light green with small or spindly bean production.

Avocado seedlings in chlorotic soils showed no signs of chlorosis when the soil was treated with 100 p.p.m. Fe.

Chlorotic gardenitas became completely green following the treatment of the soil with EDDSDE-FeNa. The old leaves turned green, and new bright green leaves appeared. Sunflower plants and citrus seedlings also favorably responded to 150 p.p.m. Fe. Excellent results are obtained with EDDSDE-FeNa, using 60 p.p.m. Fe. Smog damaged plants treated with ethylenediamine tetracetic ferric chelate much more than those treated with EDDSDE-FeNa.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications will be obvious to those skilled in the art.

We claim:

1. A compound selected from the group consisting of:

(a) a compound of the formula wherein A and A are members of the group consisting of lower alkylene and lower alkylene-phenylene-lower alkylene groups: Y Y and Y are members of the class consisting of alkyl, alkylaryl, hydroxyalkyl, hydroxyalkylaryl, hydroxyalkyloxyaryl, carboxyalkyl, alkylcarboxylate, hydroxyalkylpolyoxyalkyl, alkylphosphonic acid, alkylphosphonate, alkylsulfonic acid, alkylsulfonate, and hydrogen groups, and at least one of Y and Y is not hydrogen; k is a positive integer of not less than 1 and not more than 7; Z and Z are saturated acyclic bis-adduction groups derived from the class consisting of lower alkenyl 1,4 conjugated polycarboxylic acids having at least 2 and not more than 3 carboxyl groups, and salts thereof;

(b) chelates of the product of (a) and a polyvalent metal ion; and

(c) esters of the product of (a) and a lower alkyl group.

2. A compound of the formula:

wherein A and A are members of the group consisting of lower alkylene and lower alkylene-phenylene-lower 4. The product:

alkyl allkyl N-lower alkylene-phenylene-lower alkyleue-N H -C 0 1H H --O 01H Hz OOIH H: CO:H

5. The product:

alkyl alkyl ullkyl N -lower nlkyleue N-lower nlkylenelx-N H C 0 ;H H -C 01H H: -C 02H H: C 01H wherein (a) x is a positive integer of l-6, (b) each lower alkylene radical in the bracketed moiety may difier, and (c) each repeating bracketed moiety may differ from the preceding one. 6. The product:

OHlOHflOH CHaCHaOH N-lower aIkylene-N H -CO:M Hb-CDgM m -OoIM H: C0,M wherein M M M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

wherein M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

8. The product:

OHzC 02M GHQ-N -10wer alkylene-N-lower alkylcne-N-AJHC OiM H; H: C HQOHzO H wherein M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

9. The product:

CH: C 1M --lower elk ylcne- N- I:I O 0 :M

Hr C H C1120 H wherein M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

10. The product:

C1126 02M! lower madame-[N H- (1 02M Hiomcmon wherein M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

l 1. The product:

CHQGOzM lower alkylene-[N-CH (I 0 1M'] momma I wherein M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

12. The product:

28 wherein M M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

13. The product:

GHzCOzM lower amylase-[N H-C 011W] HzPOsM 2 wherein M M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

14. The product:

wherein M M M M M and M are members of the group consisting of hydrogen, salt forming substituents and lower alkyl substituents.

15. Chelate of a compound of claim 2 and polyvalent metal ion.

16. Ester of a compound of claim 2 and lower alkyl radical.

17. Metal salt of the product of claim 3.

18. Chelate of the product of claim 3 and polyvalent metal ion.

19. Ester of the product of claim 3 and lower alkyl radical.

20. Metal salt of the product of claim 4.

21. Chelate of the product of claim 4 and polyvalent metal 10m.

22. Ester of the product of claim 4 and lower alkyl radical.

23. Metal salt of the product of claim 5.

24. Chelate of the product of claim 5 and polyvalent metal ion.

25. Ester of the product of claim 5, and lower alkyl radical.

References Cited in the file of this patent UNITED STATES PATENTS 2,195,974 Reppe Apr. 2, 1940 2,532,391 Bersworth Dec. 5, 1950 2,568,876 White et a1. Sept. 25, 1951 2,761,874 Bersworth ct a1 Sept. 4, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,077,487 February 12, 1963 William M. Ramsey et al-.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, lines 1 and 2, and in the heading to the printed specification line 7, for "Charles Kerzerian", each occurrence, read Charles Kezerian column 2, lines 63 and 73, the term "radical" presently included in each of the formulas shown should appear in the same type size as the body of the specification and not in the smaller type size of the formulas; column 3, lines 49 and 50, for

'colnmn line54,f0r "gardenitas" read gardenias column 26,

line 3, for "groups:" read groups;

Signed and sealed this 10th day of December 1963.

(SEAL) Attest: ERNEST W. SWIDER a EDWIN L. REYNOLDS Attesting Officer Acting Commissioner of Patents 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF: (A) A COMPOUND OF THE FORMULA 